Balance training footwear

ABSTRACT

A method and apparatus for footwear that may be used for balance training or muscle strengthening, particularly, for example, in the game of golf. The footwear includes a sole having a toe portion and a heel portion, each of the toe and heel portions including an upper surface and a lower surface. The toe and heel portions may form an integrates sole and/or a coupling mechanism may be provided that adjustably couples the toe portion to the heel portion. At least one of the toe portion and heel portion includes an angled edge adjacent to the lower surface that allows pivoting of the footwear in a forward pivot direction, a backward pivot direction and/or a side cant direction. The footwear may be a sandal having straps for being worn over a shoe and/or may be incorporated into a sole during the manufacture of a shoe.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent application Ser. No. 11/488,283, filed Jul. 18, 2006, (pending), which is incorporated herein by reference.

TECHNICAL FIELD

This application is directed to the field of balance training and muscle strengthening and, more particularly, to a method and apparatus for balance training footwear.

BACKGROUND OF THE INVENTION

It is known that special footwear may be used to provide a rocking motion that allows for exercise, muscle strengthening and other therapeutic effects. (See, for example, U.S. Pat. Nos. 4,206,558 to Bivona; 5,339,542 to Kim; 5,507,106 to Fox; 5,826,351 to Tsuji; and 6,421,935 to Bartlett, which are all incorporated herein by reference.)

Further, maintaining balance is a desirable skill in many athletic games and events. In particular, in the game of golf, maintaining proper balance during a golf swing may result in a swing having improved accuracy, consistency and/or power.

Accordingly, it is desirable to provide for a system that facilitates balance training and muscle strengthening and that may be used to improve athletic performance, for example, as in the game of golf.

SUMMARY OF THE INVENTION

According to the system described herein, footwear for balance training or muscle strengthening includes a sole having an upper surface, a lower surface, a front portion, a back portion and at least two side portions. At least one of the front portion and the back portion includes an angled edge portion adjacent to the lower surface that allows pivoting of the sole in a forward to backward direction. At least one side of the sole includes a angled side edge portion that allows canting of the sole in a side to side direction. The footwear may include at least one attachment mechanism for positioning the sole on a shoe or foot. The footwear may be a shoe and further include an upper coupled to the sole. The sole may include a toe portion and a heel portion and a coupling mechanism that adjusts a spacing between the toe portion and the heel portion to control a size of the sole and which may be a threaded rod, a portion of which is received by each of the heel and toe portions.

The angled edge portion of the front portion or back portion may be angled in a range of approximately 10 degrees to approximately 50 degrees. The angled side edge portion of the side portion may be angled in a range of approximately greater than 0 degrees and less than or equal to approximately 10 degrees. Both the front portion and the back portion may include an angled edge portion. The angled portions of the front, back and/or side portions may have a non-linear profile. The side portion may include a medial side edge having a first side edge portion and a lateral side edge having a second angled side portion. The first and second angled side edge portions of the medial side edge and lateral side edge may be disposed off center from a centerline of the sole and may be at different angles from each other, including 6 to 8 degrees on one side edge and 0 to 4 degrees on the other side edge. At least one spike may be disposed on the lower surface of the sole.

According further to the system described herein, a method of balance training or muscle strengthening includes providing a pair of footwear. Each piece of footwear of the pair of footwear includes a sole that is pivotable in a side cant direction and at least one of: a forward pivot direction and a backward pivot direction. Each piece of footwear may include a sole having a toe portion and a heel portion, each having an upper and a lower surface. The size of the footwear may be adjusted by altering a spacing between the toe portion and the heel portion using a coupling mechanism. A front portion of the sole may include a front angled edge portion and a back portion of the sole may include a back angled edge portion. The sole may include at least one angled side edge portion on at least one of a medial side of the sole and a lateral side of the sole.

According further to the system described herein, a method of manufacturing balance training footwear includes providing a sole having an upper surface, a lower surface, a front portion, a back portion and at least two side portions. At least one angled edge portion may be manufactured adjacent to the lower surface in at least one of: a front portion of the sole and a back portion of the sole. At least one angled side edge portion may be manufactured adjacent to the lower surface along at least one of the side portions. Both the front portion of the sole and the back portion of the sole may include at least one angled edge portion, and both of the at least two side portions may include at least one angled side edge portion. The sole may be manufactured with a toe portion and a heel portion that are adjustably coupled. The angled side edge portion of at least one side portion may have a non-linear profile. The at least one side portion may include a medial side edge having a first angled side edge portion and a lateral side edge having a second angled side edge portion, and the first and second angled side edge portions of the medial side edge and the lateral side edge are disposed off center from a centerline of the sole. The first angled side edge portion of the medial side edge may be at a different angle than the second angled side edge portion of the lateral side edge.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the system are described with reference to the several figures of the drawings, described as follows.

FIG. 1 is a schematic illustration of a top-down view of a sandal for facilitating balance training and muscle strengthening according to one embodiment of the system described herein.

FIGS. 2A and 2B are schematic illustrations of side views of the sandal shown in FIG. 1.

FIG. 3 is a schematic illustration of a bottom-up view of the sandal shown in FIGS. 1 and 2.

FIGS. 4A and 4B are schematic illustrations of a front and side view of a sandal with another embodiment of a spring configuration according to the system described herein.

FIGS. 5A and 5B are schematic illustrations of a front and side view of a sandal with another embodiment of a spring configuration according to the system described herein.

FIG. 6 is a schematic illustration of a side view of a sandal with another embodiment of a spring configuration according to the system described herein.

FIG. 7 is a schematic illustration of a front view of a sandal according to another embodiment of the system described herein.

FIGS. 8A-C are schematic illustrations of a bottom view, side view and rear view of a sandal according to another embodiment of the system described herein.

FIG. 9 is a schematic illustration of an applied sandal system showing a sandal strapped to a shoe according to the system described herein.

FIGS. 10 and 11 are schematic illustrations showing end views of footwear soles for a front foot and back foot as seen looking from the back of the soles according to embodiments of the system described herein.

FIGS. 12 and 13 are schematic illustrations of footwear soles as viewed looking at the lower surface (bottom) of each sole according to embodiments of the system described herein.

FIG. 14 is a schematic illustration of a footwear sole as viewed from the lower surface (bottom) of the sole showing a dividing interface having a non-linear profile according to an embodiment of the system described herein.

FIG. 15 is a schematic illustration of a footwear sole as viewed from the lower surface (bottom) of the sole showing a single sole without separable toe and heel portions according to an embodiment of the system described herein.

FIG. 16 is a schematic illustration of a shoe integrated with a sole according to an embodiment of the system described herein.

FIG. 17 is a schematic illustration of a shoe to a sole is attached according to an embodiment of the system described herein.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not meant to be restrictive of the system described herein. It may be noted that, as used in the specification and the appended claims, the singular forms “a”, “an” and “the” include plural referents unless the context clearly dictates otherwise. References cited herein are hereby incorporated by reference in their entirety.

Referring now to the figures of the drawing, the figures comprise a part of this specification and illustrate exemplary embodiments of the described system. It is to be understood that in some instances various aspects of the system may be shown schematically or may be exaggerated or altered to facilitate an understanding of the system.

FIG. 1 illustrates a top-down view of a sandal 100 for facilitating balance training and muscle strengthening according to one embodiment of the system described herein. In various embodiments, the sandal 100 may be any suitable footwear that may be positioned over a foot or shoe and attached thereto. The sandal 100 may include a toe portion 110 and a heel portion 120 coupled together by a mechanism 130 that allows for size adjustment, for example a threaded mechanism, as further described elsewhere herein. The portions 110, 120 may be approximately the same size or may be differently sized. Alternatively, the sandal may include only one integral sole portion.

In various embodiments, the sole of the sandal may be one inch thick, but may range from one-half inch to one and one-half inches in thickness. The core material of the sole may vary and may include 50% wood fiber with 50% polyethylene composite, PVC, nylon, wood, aluminum, fiberglass, rubber, and/or any other appropriate material, such as any hard machineable material. The upper and lower surfaces may have a frictional or no-slip surface 112, 122 either applied or impregnated based on the particular core material used. For example, the surfaces 112, 122 may include a dense foam or rubber surface that partially or fully forms to the contact surface of an applied shoe or foot, thereby facilitating the frictional or no-slip functionality of the interface between the sandal and the applied shoe or foot.

The sole may be split into two portions, approximately the same size, as the toe portion 110 and the heel portion 120. The two portions 110, 120 may be connected by the coupling mechanism 130, such as installing an installed threaded insert or drilling and taping the sole material (shown as an internal cavity 132, see FIGS. 2A and 2B, as further described elsewhere herein) and then using a threaded rod to connect the two portions 110, 120. Other known coupling mechanisms may also be used. The coupling mechanism 130 provides for size adjustment capability of the sandal and allows individual adjustment for each user. The threaded rod used may be a three-eighths inch width rod with sixteen threads per inch. In other embodiments, the threaded rod may be varied from a one-quarter inch rod to a one-half inch rod and include any known thread configuration. The threaded rod's length may vary from two inches to six inches, although a three inch rod and a four and one-half inch rod may cover a wide range of shoe sizes. The sizing of the soles taper and width and length pieces may be varied according to male, female, and child sizing. The threaded rod size and length may also be varied based on male, female or child sizing. The shape of the sole, as shown in the illustrated top-down view of FIG. 1, may conform to the natural flaring out of the soles of most sneakers, golf shoes, hiking shoes, etc., at the toe portion 110 and heel portion 120.

FIGS. 2A and 2B illustrate side views of the sandal 100. As shown, the surface which comes in contact with the shoe may remain flat. The surface which comes in contact with the ground may taper down at front and back pivot angles 160, 162 of approximately thirty-five degrees sloping down towards the toe and heel. In other embodiments, the angles may be in a range of approximately ten degrees to approximately fifty degrees, or a range of approximately fifteen to forty-five degrees, although any appropriate angle may be used. The angle 160 of the toe portion 110 may be the same as or different from the angle 162 of the heel portion 120. It is further contemplated herein that the sandal may have only a front pivot angle (only angle 160 of the toe portion 110) with little or no angle at the heel portion 120 or only a back pivot angle (only angle 162 of the heel portion 120) with little or no angle at the toe portion 110.

A comparison of FIG. 2A with 2B illustrates the size adjustment features of the sandal 100 according to the system described herein. In FIG. 2A, the sandal 100 is shown in an elongated size position in which most of the threaded rod coupling mechanism 130 is used to generate a relatively large spacing between the toe portion 110 and the heel portion 120. In FIG. 2B, the sandal 100 is shown in a compacted size position, with a relatively small spacing between the toe portion 110 and the heel portion 120, in which most of the threaded rod coupling mechanism 130 is contained within the internal cavities 132 of each of the toe portion 110 and the heel portion 120. The size adjustment capability allows for not only adjustment according to the physical size needs of a golfer, but also allows for variable intensity of the balance training experience. That is, generally, the smaller the size setting of the sandal the more difficult it is for a golfer to balance him or herself during the golf swing. Thus, a golfer may initially set the sandal at a relatively larger size position and, thereafter, reduce the spacing between the toe portion 110 and heel portion 120 to increase the intensity of the training and/or exercise experience.

The sandal 100 may include side spikes 172 attached to springs 170 that may be seven-eighths inch in diameter by seven-eighths to one and one-quarter inches in height with a wire size that may range between 0.05 and 0.14 inches, although other ranges are possible. In one embodiment, the standard size is 0.08 inches. The player's weight and/or strength may determine what wire size is comfortable for the player. The springs 170 may be compression or wave springs with equal or varying spring rates, for example as measured in pounds/inch and/or load measured in pounds.

FIG. 3 is a schematic illustration of a bottom-up view of the sandal 100 showing two springs 170 and spikes 172 on each of the toe 110 and heel 120 portions of the sandal 100. For example, the spikes and springs may be attached to the rear foot sandal (right foot for right handed players, left foot for left handed players).

The springs 170 may be useful in connection with training of the golfer. On the back swing, the golfer may feel the sensation of compressing the springs loading the players weight properly on the back foot. On the forward swing, the springs 170 may help to force the golfer to transfer the weight to the front foot and keep it there, while remaining balanced with proper weight distribution throughout the swing. The springs 170 may be press fit into a seven-eighths inch hole drilled one-quarter to three-eighths inches deep. Spacers may be placed in the hole under the spring if more projection is desired.

Alternatively, the spikes 172 may be inserted, without springs, directly onto the flat portion of the sole which comes in contact with the ground. The spikes 172 may be threaded, or inserted through another means, into each bottom portion, front and back halves, of the sandal. It is also contemplated to use springs 170 without spikes.

Other configurations of the springs and spikes are possible and contemplated herein. For example, FIGS. 4A and 4B show schematic illustrations of a front view (FIG. 4A) and side view (FIG. 4B) of a sandal with another embodiment of a spring and spike configuration according to the system described herein. As shown in the front view of the sandal in FIG. 4A, the sandal may include a spring 170 on one side of the base of the toe portion 110 (and/or heel portion) and a base support surface 174 attached thereto such that the base support element 174 and spring 170 form a canted bottom surface of the sandal having a cant angle that changes with compression of the spring. Spikes 172 may be attached to the bottom surface of the bottom support element 174. In this manner, further balance training may be provided in a side-to-side direction as a result of the canted bottom surface of the sandal.

Alternatively, a similar configuration as described above may be incorporated into the top surface of the sandal, that is, the surface in contact with the golfer's shoe. FIG. 5A illustrates a front view and FIG. 5B illustrates a side view of a sandal according to another embodiment of the system described herein showing a spring 170 on one side of the toe portion 110 (and/or heel portion) and a top support surface 176 attached thereto such that the top support element 176 and spring 170 form a canted top surface of the sandal having a cant angle that changes with compression of the spring, for example with maximum cant when the spring is in an uncompressed state. Spikes 172 may be attached to the bottom surface of the sandal. In this manner, further balance training may be provided in a side-to-side direction as a result of the canted top surface of the sandal.

It is further contemplated herein that spring configurations may be provided that facilitate the forward and backward pivot angling of the sandal. For example, FIG. 6 is a side view illustrating a spring configuration for the sandal 100 in which a base support surface 178 is coupled to a spring 170 such that it facilitates angling in the forward and backward pivot directions of the sandal and is configurable for use on the toe portion 110 and/or the heel portion 120 as shown.

FIG. 7 is a schematic illustration of a front view of a sandal 200 according to another embodiment of the system described herein. In the illustrated embodiment, a toe sole portion 210 of the sandal 200 is shown from a front view having cant angles 260 and 262 included on the inside (medial) and outside (lateral) edges of the toe sole portion. In various embodiments, the cant angles 260 and 262 may range from approximately ten degrees to approximately fifty degrees, or a range of approximately fifteen to forty-five degrees, although any appropriate angle may be used. In other embodiments, the cant angles 260 and 262 may range from 0 degrees to 10 degrees and be specifically configured according to the whether the canted portions are on a toe or heel portion, on the inside (medial) and outside (lateral) edges of the heel or toe portion, and/or whether the sandal 200 is for a right or left handed golfer, as further described elsewhere herein. A heel portion of the sandal 200 may have similar cant angles on the inside (medial) and outside (lateral) edges. The sandal also may include springs 270 and spikes 272 configured as described elsewhere herein. As a result, the sandal 200 may provide balance training and muscle strengthening for a golfer balancing in the side-to-side directions. Consequently, a sandal according to the system described herein may facilitate balancing in the forward and backward directions as a result of the toe and heel pivot angles (160, 162, see FIG. 1) and the side directions as a result of the cant angles 260 and 262. It is further contemplated herein that the sandal may have only one side edge cut with a cant angle (for example, only cant angle 260 or only cant angle 262).

The top face of the sandal's sole which comes in contact with the shoe's sole may have a recessed area 150 on both front corners (see FIGS. 1 and 2) which may allow for the golf shoe spikes to recess into the sandal 100 thereby accommodating the shoe spike to provide for a comfortable fit of the sandal with standard golf shoes and for protecting the shoe spike from damage.

FIGS. 8A-C are schematic illustrations of a bottom view (FIG. 8A), side view (FIG. 8B) and rear view (FIG. 8C) of a sandal 300 according to another embodiment of the system described herein. In the illustrated embodiment, a ridge 380 is shown positioned on the bottom of the sole of the toe 310 and heel 320 portions of the sandal 300. The ridge 380 is shaped to provide an aid for additional medial/lateral balance training and muscle strengthening mechanism of the sandal 300 that facilitates balance in a side-to-side cant direction, for example by having a rounded surface that contacts the ground. In an embodiment herein, the ridge 380 may vary from one-quarter to one-half inches in width and one-quarter to three-quarters inches in height. The outer ends of the ridge 380 may follow the existing taper of the front and rear edges of the toe 310 and heel 320 portions, as shown. The ridge 380 may be used independently or in conjunction with other balance and muscle strengthening mechanisms detailed herein.

Referring now back to FIG. 1, the sandal may include straps 140, 142 that are made of nylon or leather or any other suitable material which may allow the golfer to firmly attach the sandal to the bottom of the shoe without risk of failure. One strap 140 may be attached to the front sole portion 110 just behind the projection by the ball of the foot. The strap 140 may then wrap around the foot and be firmly attached. Another strap 142 may be attached to the heel sole portion 120 which may go over and around the heel of the shoe and firmly attached. A third strap 144 (see FIG. 9, as described elsewhere herein) may be attached to the rear strap two to three inches up the rear heel strap approximately perpendicular thereto and facing towards the front of the player and secured around the ankle.

The straps described herein may be one or more of the following mechanisms: hook and loop, a buckle system with a ladder lock, quick release cam, metal cam anchor, and/or a sure lock metal tooth buckle system. Other appropriate mechanisms may also be used. The strap mechanisms may provide proper tightening while minimizing risk of unintended release. A buckle system 146 is illustrated in FIG. 9 to provide tightening of the straps.

The size of the sandal 100 may be adjusted for length of the player's foot using the size control features of the coupling mechanism 130, as described elsewhere herein. The sandal may reach the center of the ball of the foot to the front third of the foot's heel. The sizing may be varied based on the balancing requirements of the player.

The following describes an example method for attaching the sandal to a shoe. The toes and ball of the foot may be placed firmly on the ground. The sandal may be placed against the sole of the shoe, and the front portion may be wedged down to the ground between the ground and the ball of the foot. The front toe strap may be attached firmly. Then, the heel strap may be attached firmly. Finally, the ankle strap may be attached firmly to the foot. The process may be repeated for the other foot. The sandals are now on properly and ready for use.

FIG. 9 is a schematic illustration of an applied sandal system 400 showing a foot or shoe on which is strapped a sandal according to the system described herein (for example, sandal 100). Other elements are identified in FIG. 9 as described elsewhere herein in reference to the other figures.

The following embodiment details the use and benefits of the sandals during a golf swing (described for a right handed golfer). First, a golfer (or other user) places their feet a comfortable distance apart with the front foot's toe pointing partway towards the target. With hands and club in front, the golfer may be positioned in the proper balanced posture. For a few practice swings, the golfer may use swings of partial power or intensity to become comfortable with the sandals before commencing the primary swing. On the back swing, the golfer may get the feeling of weight shifting to the back foot. The weight shift may compress the springs in the sandal. Thus, the golfer's body may be balanced but the majority of the golfer's weight is on the back foot and the golfer's body is coiled backwards onto the back leg, thereby storing power for the swing. The golfer's hands and club should be over the right shoulder at the top of the back swing. With the back swing completed, the golfer may then start the forward swing with a hip turn and weight shift from the back to the front foot, while the sandals force the golfer to maintain balance. The club head path is desirably kept inside the target line throughout the swing until impact with the ball. Generally, the head of the club should be kept heading towards, or just to the right of, the target as long as possible. The swing is usually finished with the golfer's hands and club over the left shoulder with the golfer's weight primarily on the left foot.

FIGS. 10 and 11 are schematic illustrations showing end views of soles 500, 500′ that be used with footwear for a front foot and/or a back foot as viewed looking from the back of the sole according to embodiments of the system described herein. In the illustrated embodiment, the configuration of the soles are shown for a right-handed golfer in which the sole 500 is for the front foot of a right handed golfing stance and the sole 500′ is for the back foot of a right handed golfing stance. However, the system described herein is applicable to footwear for right handed and/or left handed golfers. Accordingly, in the case of footwear for a left-handed golfer, measurements as between medial and lateral sides of the sole, as described herein for footwear for a right-handed golfer, may be switched or otherwise appropriately modified for footwear for a left-handed golfer. Each of the soles 500, 500′ illustrated may be one integrated sole, such as the bottom of a shoe, and/or may be the sole of a sandal and be divided into toe and heel portions, as further discussed elsewhere herein. Each of the toe and heel portions may be configured with angled portions on the medial and lateral sides, as set forth below, and/or each the heel and toe portions of each sole 500, 500′ may have different angled portion configurations thereon.

In FIG. 10, the front foot sole 500 is shown having a medial side (inside) portion 502 with an angle 512 and a lateral side (outside) portion 504 with an angle 514 in which angles as shown with respect to horizontal ground. A dividing interface 505 between the medial side portion 502 and the lateral side portion 504 is shown as being along a centerline 501 of the sole 500. In FIG. 11, the back foot sole 500′ is shown as having a dividing interface 505′ between a medial side portion 502′ and a lateral side portion 504′ as being off center from a centerline 501′. In the illustrated embodiment, the medial side portion 502′ of the back foot sole 500′ is shown as being wider than the lateral side portion 504′; however, the medial and side portions described herein may be appropriately sized differently than shown according to particular golfer and/or design specifications.

The angles 512, 512′ of the medial side portions 502, 502′ and the angles 514, 514′ of the lateral side portions 504, 504′ may be substantially equal or may be different in order to facilitate balance training functions. In various embodiments, each of the angles 512, 512′ and the angles 514, 514′ may be in a range from greater than zero degrees to approximately ten degrees. For example, each of the angles 512, 512′ may be in a range of five to eight degrees, and specifically approximately six or seven degrees, and each of the angles 514, 514′ may be in a range of zero to four degrees, and specifically two or three degrees. Balance training for purposes of improving a golf swing may be facilitated, in some instances, by having the angles 512, 512′ of the medial side portions 502, 502′ be larger than the angles 514, 514′ of the lateral side portions 504, 504′ for the soles 500, 500′ for each of the front foot and back foot in a golfing stance. Alternatively, in other instances, balancing training may be facilitated by having the angles 512, 512′ of the medial side portions 502, 502′ be smaller than the angles 514, 514′ of the lateral side portions 504, 504′. For example, the angles 512, 512′ may be in the range of zero to four degrees, and specifically approximately two or three degrees, and the angles 512, 512′ may be in the range of five to eight degrees, and specifically approximately six or seven degrees. Angles other than those specifically mentioned above may be used to facilitate balance training in accordance with the system described herein, including angles greater than 10 degrees as further discussed elsewhere herein.

FIGS. 12 and 13 are schematic illustrations of the footwear soles 500, 500′ as viewed looking at the lower surface (bottom) of each sole 500, 500′ according to embodiments of the system described herein. As noted herein in reference to the FIGS. 10 and 11, the sole 500 is illustrated for the front foot of a right-handed golfer, and the sole 500′ is illustrated for the back foot of a right-handed golfer. Each of the soles 500, 500′ may include toe portions 510, 510′ and heel portions 520, 520′ that coupled together by coupling mechanisms 530, 530′, as further discussed elsewhere herein. Each of the toe portions 510, 510′ and heel portions 520, 520′ may have the medial side portions 502, 502′ and lateral side portions 504, 504′ discussed herein and separated by dividing interfaces 505, 505′. Springs 570 and/or spikes 572, like the springs 170 and spikes 172 discussed herein, may be disposed on the lower surfaces of each of the toe portions 510, 510′ and the heel portions 520, 520′ and may include springs 570, 570′ and/or spikes 572, 572′ disposed directly over the dividing interfaces 505, 505′ that may be advantageously positioned to increase the effectiveness of the angled portions of the medial side portions 502, 502′ and lateral side portions 504, 504′. The toe portions 510, 510′ may include a front edge portion 515, 515′ having a forward pivot angle as further discussed elsewhere herein and the heel portions 520, 520′ may include a back edge portion 525, 525′ having a backward pivot angle as further discussed elsewhere herein.

FIG. 14 is a schematic illustration of a footwear sole 600 as viewed from the lower surface (bottom) of the sole showing a dividing interface having a non-linear profile according to an embodiment of the system described herein. For example, in the illustrated embodiment, a “C” line interface 605 is shown on each of a toe portion 610 and a heel portion 620 that divides the medial side portion 602 and the lateral side portion 604 that may be angled in a manner similar to that discussed elsewhere herein. Other non-linear profiles may be used. As illustrated, the toe portion 610 has a front edge portion 615 with a forward pivot angle and the heel portion 620 has a back edge portion 625 with a backward pivot angle. It should also be noted that either or both of the front edge portion 615 or the back edge portion 625 may also have a non-linear profile.

FIG. 15 is a schematic illustration of a footwear sole 700 as viewed from the lower surface (bottom) of the sole showing an integrated toe/heel portion 710 without an adjustable coupling mechanism according to an embodiment of the system described herein. The integrated toe/heel portion 710 may include a front angled edge 715 and a back angled edge 725 and which may be divided into a medial side portion 702 and a lateral side portion 704 configured as discussed elsewhere herein.

FIG. 16 is a schematic illustration of a shoe 800 having an upper 810 integrated with the sole 700, among other known shoe components, according to an embodiment of the system described herein. In an embodiment, the shoe 800 may be a golf shoe having the integrated sole 700 incorporated into a particular shoe used by a golfer (e.g., male/female, adult/child, left-handed golfer/right-handed golfer). The sole 700 may be sized according to the size of the shoe 800 with which it is integrated with the shoe, for example, at the time of manufacture.

FIG. 17 is a schematic illustration of a shoe 1000 having an upper 1010 to which a sole 900 has been attached, among other known shoe components, according to an embodiment of the system described herein. The sole 900 may include a toe portion 910 and a heel portion 920, as discussed herein, and which may be attached to the upper 1010 of the shoe 1000 by attachment mechanisms 911, 921. The attachment mechanisms 911, 921 may be screw attachments, snap attachments and/or other attachment mechanisms, such that each of the toe portion 910 and the heel portion 920 may be screwed or otherwise attached to the bottom of the upper 1010, or even into the bottom of a pre-existing sole of a shoe, in a manner similar, for example, to the attachment of spikes to the bottom of a golfer's shoe. Alternatively, the sole 900 may be a single unit, like that described elsewhere herein, that is attached as a single unit to the bottom of the shoe 1000 with one or more attachments.

While swinging, the importance of achieving good balance and weight distribution may be conveyed to the golfer by the feel of the footwear. Over the course of the swing, a proper swing path, from inside to out, may be maintained, during which, while the golfer attempts to maintain his balance, the footwear provides balance training, muscle strengthening and builds desirable muscle memory. As detailed herein, the golfer may be forced to maintain balance to address the forward and backward pivoting provided by the footwear, and/or the golfer may be forced to maintain balance to address the side canting provided by the footwear. As a result of utilization of the present system, the golfer may gain and foster foundational swing skills through mental awareness of desirable swing dynamics.

Other embodiments of the invention will be apparent to those skilled in the art from a consideration of the specification or practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit of the invention being indicated by the following claims. 

1. Footwear for balance training or muscle strengthening, comprising: a sole having an upper surface, a lower surface, a front portion, a back portion and at least two side portions, wherein at least one of the front portion and the back portion of the sole includes an angled edge portion adjacent to the lower surface that allows pivoting of the sole in a forward to backward direction, and wherein at least one side portion of the sole includes an angled side edge portion adjacent to the lower surface that allows canting of the sole in a side to side direction.
 2. The footwear of claim 1, wherein the footwear further includes at least one attachment mechanism for positioning the sole on a shoe or foot.
 3. The footwear of claim 1, wherein the footwear is a shoe and further includes an upper coupled to the sole.
 4. The footwear of claim 1, wherein the sole further includes a toe portion and a heel portion.
 5. The footwear of claim 4, further comprising: a coupling mechanism that adjusts a spacing between the toe portion and the heel portion to control a size of the sole.
 6. The footwear of claim 5, wherein said coupling mechanism includes a threaded rod, and wherein the toe portion and the heel portion receive at least a portion of the threaded rod.
 7. The footwear of claim 1, wherein the angled edge portion of the at least one of the front portion and the back portion is angled in a range of approximately 10 degrees to approximately 50 degrees.
 8. The footwear of claim 1, wherein the angled side edge portion of the at least one side portion is angled in a range of approximately greater than 0 degrees and less than or equal to approximately 10 degrees.
 9. The footwear of claim 1, wherein both the front portion and the back portion include an angled edge portion.
 10. The footwear of claim 1, wherein the angled portion of the at least one of the front portion and the back portion has a non-linear profile.
 11. The footwear of claim 1, wherein the angled side edge portion of the at least one side portion has a non-linear profile.
 12. The footwear of claim 1, wherein the at least one side portion includes a medial side edge having a first angled side edge portion and a lateral side edge having a second angled side edge portion.
 13. The footwear of claim 12, wherein first and second angled side edge portions of the medial side edge and the lateral side edge are disposed off center from a centerline of the sole.
 14. The footwear of claim 12, wherein the first angled side edge portion of the medial side edge is at a different angle than the second angled side edge portion of the lateral side edge.
 15. The footwear of claim 14, wherein the first angled side edge portion of the medial side edge is at an angle in a range of approximately 6 to 8 degrees and the second angled side edge portion of the lateral side edge is at an angle in a range of approximately of approximately 0 to 4 degrees.
 16. The footwear of claim 14, wherein the second angled side portion of the lateral side edge is at an angle of in a range of approximately 6 to 8 degrees and the first angled side edge portion of the medial side edge is at an angle in a range of approximately of approximately 0 to 4 degrees.
 17. The footwear of claim 1, further comprising: at least one spike disposed on the lower surface of the sole.
 18. A method of balance training or muscle strengthening, comprising: providing a pair of footwear, wherein each piece of footwear of the pair of footwear includes a sole that is pivotable in a side cant direction and at least one of: a forward pivot direction and a backward pivot direction.
 19. The method of claim 18, wherein each piece of footwear includes: a sole including a toe portion and a heel portion, each of the toe and heel portions including an upper surface and a lower surface.
 20. The method of claim 19, further comprising: adjusting a size of the footwear by altering a spacing between said toe portion and said heel portion using a coupling mechanism.
 19. The method of claim 17, wherein a front portion of the sole includes a front angled edge portion and a back portion of the sole includes a back angled edge portion.
 20. The method of claim 17, wherein the sole includes at least one angled side edge portion on at least one of a medial side of the sole and a lateral side of the sole.
 21. A method of manufacturing balance training footwear, comprising: providing a sole having an upper surface, a lower surface, a front portion, a back portion and at least two side portions; manufacturing at least one angled edge portion adjacent to the lower surface in at least one of: a front portion of the sole and a back portion of the sole; manufacturing at least one angled side edge portion adjacent to the lower surface along at least one of the side portions.
 22. The method of claim 21, wherein both the front portion of the sole and the back portion of the sole include at least one angled edge portion.
 23. The method of claim 21, wherein both of the at least two side portions include at least one angled side edge portion.
 24. The method of claim 21, further comprising: manufacturing the sole with a toe portion and a heel portion that are adjustably coupled.
 25. The method of claim 21, wherein the angled side edge portion of at least one side portion has a non-linear profile.
 26. The method of claim 21, wherein the at least one side portion includes a medial side edge having a first angled side edge portion and a lateral side edge having a second angled side edge portion, different than the first angled side edge portion.
 27. The method of claim 26, wherein first and second angled side edge portions of the medial side edge and the lateral side edge are disposed off center from a centerline of the sole. 